Triple-shelled CuO/CeO2 hollow nanospheres derived from metal–organic frameworks as highly efficient catalysts for CO oxidation

Abstract

Developing advanced nanocatalysts with superior structural and textural characteristics can provide significant potential for CO oxidation. Herein, triple-shelled CuO/CeO₂ hollow nanospherical catalysts have been successfully prepared through a metal–organic framework (MOF) engaged strategy, involving two steps: thermal annealing of CeMOF precursors and subsequent deposition–precipitation of CuO. By tuning the loading of CuO species, the composites show a typical volcano-shaped relationship between the composition and the catalytic activity. CuO/CeO₂-8% is the most active catalyst with the lowest temperature (130 °C) to achieve complete CO conversion, and it possesses the maximum turnover frequency (TOF) value of 1.72 × 10⁻³ s⁻¹ at 90 °C. Systematic structural characterization revealed that the remarkably improved catalytic performance can be attributed to a unique porous triple-shelled structure, abundant surface oxygen vacancies, greater Cu⁺ content, more lattice oxygen and the synergistic effect between two individual components. Furthermore, the superior catalyst also has good cyclic stability. Of significance, this work may open a novel, facile avenue for fabricating desirable multicomponent nanocatalysts from proper MOFs for pollution control and environment protection.